客户端/服务器用户名/密码认证

Question

我正在开发客户端/服务器身份验证程序，但是遇到了问题。客户端可以很好地与服务器建立连接，但是一旦我输入密码和用户名，它就不会返回有效的用户名/密码。如果用户使用正确的用户名/密码服务器登录，则应返回“
Welcome，username”，如果无效，则返回“登录失败”。我查看了printwriter和bufferedreader文档，以确保我使用正确的方法在服务器/客户端之间正确传递文本。我尝试通过在服务器和客户端上同时打印用户名和密码来进行调试，以确保它们都在侦听/写入，因为它们确实会打印出正确的用户名/密码，因此它们似乎在监听/写入。有人可以给我一些我要去哪里的见解吗？

public class Connect {
    private String USERNAME = "java";
    private String PASSWORD = "java";
    private int PORT = 9090;
    private String HOSTNAME = "localhost";

    public String getUsername(){
        return this.USERNAME;
    }

    public String getPassword(){

        return this.PASSWORD;
    }

    public int getPort(){
        return this.PORT;
    }

    public String gethostName(){
        return this.HOSTNAME;
    }
}






import java.io.*;
import java.io.net.*;
public class Client {
    private final String FILENAME = null;
    Connect c = new Connect();
    Socket socket;
    BufferedReader read;
    PrintWriter output;

    public void startClient() throws UnknownHostException, IOException{
        //Create socket connection
        socket = new Socket(c.gethostName(), c.getPort());

        //create printwriter for sending login to server
        output = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));

        //prompt for user name
        String username = JOptionPane.showInputDialog(null, "Enter User Name:");

        //send user name to server
        output.println(username);

        //prompt for password
        String password = JOptionPane.showInputDialog(null, "Enter Password");

        //send password to server
        output.println(password);
        output.flush();

        //create Buffered reader for reading response from server
        read = new BufferedReader(new InputStreamReader(socket.getInputStream()));

        //read response from server
        String response = read.readLine();
        System.out.println("This is the response: " + response);

        //display response
        JOptionPane.showMessageDialog(null, response);
    }

    public void fileInfo(){

    }

    public static void main(String args[]){
        Client client = new Client();
        try {
            client.startClient();
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}






import java.io.*;
import java.io.net.*;
public class Server {
    private int currentTot;
    ServerSocket serversocket;
    Socket client;
    int bytesRead;
    Connect c = new Connect();
    BufferedReader input;
    PrintWriter output;

    public void start() throws IOException{
        System.out.println("Connection Starting on port:" + c.getPort());
        //make connection to client on port specified
        serversocket = new ServerSocket(c.getPort());

        //accept connection from client
        client = serversocket.accept();

        System.out.println("Waiting for connection from client");

        try {
            logInfo();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public void logInfo() throws Exception{
        //open buffered reader for reading data from client
        input = new BufferedReader(new InputStreamReader(client.getInputStream()));

        String username = input.readLine();
        System.out.println("SERVER SIDE" + username);
        String password = input.readLine();
        System.out.println("SERVER SIDE" + password);

        //open printwriter for writing data to client
        output = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));

        if(username.equals(c.getUsername()) &&password.equals(c.getPassword())){
            output.println("Welcome, " + username);
        }else{
            output.println("Login Failed");
        }

    }
    public static void main(String[] args){
        Server server = new Server();
        try {
            server.start();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }       
}

Answer 1

您还需要刷新服务器的printWriter，就像在客户端一样。

在loginfo()方法结束时，

if(username.equals(c.getUsername()) &&password.equals(c.getPassword())){
    output.println("Welcome, " + username);
}else{
    output.println("Login Failed");
}
output.flush();
output.close();